Non-rotating drill pipe protector



Aug. 13, 1968 C GRANT ET AL 3,397,017

NON-ROTATING DRILL PIPE PROTECTOR Filed Feb. 21, 1966 2 Sheets-Sheet 1 Y W 2$$Q N A \i N mvENToRs' g Y W.

Affaf/wfl J. C. GRANT ET AL NON-ROTATING DRILL PIPE PROTECTOR Aug. 13, 1968 2 Sheets-Sheet 2 Filed Feb. 21, 1966 United States Patent 3,397,017 NON-ROTATING DRILL PIPE PROTECTOR John C. Grant, Huntington Park, and Raymond G. Taylor, Jr., Santa Monica, Calif., assignors to Byron Jackson, Inc., Long Beach, Calif., a corporation of Delaware Filed Feb. 21, 1966, Ser. No. 529,073 3 Claims. (Cl. 308-4) ABSTRACT OF THE DISCLOSURE A tubular protector of elastomeric material for a Well drilling string or pipe, the protector being formed of reinforced arcuate flanged section segments with fasteners in the flanges providing means for assembling the tubular protector about the pipe. To limit longitudinal movement of the protector along the pipe, stops may be placed on the string above and below the portector.

The present invention relates to a drill string protector and more particularly to a drill string protector of the type adapted to remain stationary or non-rotative as the drill string rotates therein.

In the drilling of oil and/or gas wells and the like holes into the earth, it is the practice to fix on the drill string or drill pipe rubber sleeves which rotate with the drill string and constitute bushings or pipe protectors which serve toreduce friction caused by engagement of the drill string with the casing in the upper regions of the hole. Below the casing the use of such bushings is not practical since engagement of the protectors with the wall of the so-called open hole, that is, with the uncased well wall, causes the rapid destruction of the rotating protector.

Nevertheless, it has been found desirable that the lower sections of the drill string which rotate in the open hole be provided with protective devices which will remain stationary while the drill string revolves therein, so that 1) the drill string will be protected from engagement with the open well bore wall so as to reduce wear, and (2) the 'drill string will be stabilized in the open hole to reduce the tendency .of the string to deviate from a desired drilling direction.

More particularly, the present invention has as general objectives the provision of a non-rotating protective sleeve device within which the drill string may revolve, which 1) may be placed on the drill string at any desired location, (2) is so constructed that application of the sleeve to the drill string is a simple operation, and (3) is so constructed that following its installation the protector is not subject to loss of metal components in the hole or to becoming displaced from the drill string and, moreover, the protector is durable in construction.

More specifically, an object of the invention is to provide a protective sleeve applicable to any desired location on the drill string, for example, to a location intermediate the ends of a standard drill collar adjacent the lower end of the drill string, and without requiring the use in the drill string of a special sub or special length of drill collar tofunction as a mandrel or support for the protector. In accomplishing this objective, the protector is of a longitudinally split construction, composed of complemental sections adapted to be assembled with one another about the drill string and to be held in 'a desired longitudinally extended region of the drill string by suit-able stop collar devices which are also applicable to the drill string or drill collar at desired locations.

In addition, a specific object is the provision of a metal reinforced split protector construction which is simply applicable to the drill string by screw fasteners which interconnect the protector parts.

Still further, the interconnecting screw parts are held captive so that they may not be lost in the hole in the event 3,397,017 Patented Aug. 13, 1968 that one or more of them should loosen due to vibration, the protector construction being, however, such that inadvertent loosening of fastener screws is inhibited.

Yet another specific object is the provision of a structure which is durable in the sense that it is preferably so constructed as to be relatively insensitive to side loads and shocks to which it is inherently subjected during use, and the structure also being such that wear of the protector caused by revolution of the drill string therein is reduced to a minimum.

Other objects and advantages of the invention will be hereinafter described or will become apparent to those skilled in the art, and the novel features of the invention will be defined in the appended claims.

Briefly, the invention includes a tubular protector member capable of being applied about a portion of a well drilling string, the tubular member comprising arcuate section segments of elastomeric material, each segment including a pair of longitudinal connecting ribs of elastomeric material, each rib complementarily engaging a rib of an adjacent segment of the tubular member, the segments having rigid inserts therein, and wherein the improvement comprises: the inserts each including a pair of longitudinal edge flanges, one of each pair extending into one of each of the pairs of ribs, the ribs and the flanges having spaced aligned lateral holes therethrough; a bar embedded in the elastomeric material of one of the ribs adjacent to one of each of the pairs of edge flanges in each of the segments, the bars having longitudinally spaced fastener means; and the fastener means being engaged by fasteners through the holes in one of the ribs and the flanges for securing the flanges together in opposed relation to form the tubular member.

In the drawings:

FIG. 1 is a view in elevation, showing a non-rotating protector made in accordance with the invention applied to -a length of drill string between a pair of stop collars and disposed in an open well bore;

FIG. 2 is a view in transverse section, as taken on the line 2--2 of FIG. 1;

FIG. 3 is a view in longitudinal section, as taken .on the line 33 of FIG. 2, with a portion broken away; and

FIG. 4 is an enlarged fragmentary detail view in section, as taken on the line 4-4 of FIG. 3.

Like reference characters in the several views of the drawings and in the following description designate corresponding parts.

Referring to FIG. 1, a non-rotating, split protector or stabilizer made in accordance with the invention and generally designated P is shown as applied to a length of drill string S between an upper stop collar C and a lower stop collar C the drill string being within a well bore W which is uncased or open and t-ranverses the earth formation into which or through which the well is to be drilled. characteristically, the drill string S will be rotated to cause the advance of a drill bit (not shown) into the earth formation, as a drilling fluid or mud is circulated downwardly through the drill string and thence back to the earths surface in the annular space between the drill string and the well bore. It is the function of the present protector to stabilize the drill string within the well bore and to preclude frictional engagement of the drill string with the well wall as the drill string revolves, but without restricting the upward flow of drilling fluid returning to the earths surface.

Accordingly, the protector P comprises a generally cylindrical body 1 having a number of longitudinally extended, radially projecting and angularly spaced ribs 2 thereon. The body 1 is adapted to fit loosely about the pipe string (see FIG. 2) to permit freedom of rotation of the pipe within the protector body. In addition, the body 1 is held on the pipe for limited axial movement of the pipe within the protector as may be desirable when the pipe is being handled in the drilling derrick to add new lengths of pipe during progress of the drilling operation, all as well known in the art. For the latter purpose the stop collars C and C? are preferably secured to the pipe'string in spaced relation, as shown in FIG. 1'.

The stop collars may be of any suitable type, but-for illustrative purposes are typical hinged collar half-sections adapted to be united about the pipe and secured in position by set screws C Referring now more particularly to FIG. 2, it will be seen that the protector P is composed of similar half-parts or sections which are joined together along a longitudinal plane bisecting the body 1. Each half-part comprises a metal insert 4 embedded in the respective section of cylindrical body 1, the latter being composed of a rubber composition. The inserts 4 are bonded within the rubber body and may have a suitable number of openings 5 or other surface irregularities to assist in the formation of a mechanical interlock between the rubber and the metal insert.

Along the longitudinally extended ends of the meta insert 4, are outwardly projecting flanges 6 and 7, which are embedded in half-sections 2 and 2 respectively of a rib 2, there being a layer of rubber at 6' and 7 respectively of the mutually confronting flanges 6 and 7 when the protector parts are assembled about the pipe.

Referring to FIGS. 3 and 4 in particular, it will be noted that flange 6 is provided with a plurality of openings 8 in spaced relation along the flange and flange 7 is provided with similar openings 9, these openings 8 and 9 being alignable upon assembly of the protector so that a bolt 10 may extend through each pair of aligned openings.

Rib section 2' in which flange 6 is embedded is formed with recesses 11 for accommodation of the bolt heads 10, there being an access opening 11 into the recess 11. The access opening 11 is smaller than bold head 10 so that a shoulder 11 is formed constituting means for retaining bolt 10 captive in the recess 11 not only prior to assembly of the protector halves, but also following such assembly in the event that bolt 10 should inadventently loosen during use of the protector. However, it will be noted that access opening 11 is of suflicient size as to enable the insertion of a driving tool therethrough into driving engagement with the bolt head 10'.

Bolt 10 has a stem 10" which, when the protector halves are disposed in opposing relation with rib sections 2 and 2" of the sections abutting one another, will extend through flange openings 8 and 9 into an elongated common member 12 in the respective rib sections 2". This member is in the form of an elongated bar having threaded openings 12' for reception of the bolt stems 10", the bars being embedded in rib sections 2 and preferably being bonded to the rubber material but preferably being separate from the flanges 7 so as to be free topaitake of movement relative to the latter. In this connection, it will also be noted that openings 8 and 9 in the flanges 6 and 7 are larger than the bolt stem 10" so as to enable limited relative movement.

In alignment with the threaded Openings 12' in the respective bars 12, each rib section 2 is formed with a vent opening 13, which will prevent the entrapment of air, mud, or other fluid in the opening 12'. Thus, when bolts 10 are driven into the openings 12', fluid will be displaced through the vents 13 so that pressure may not be developed in the openings 12', which pressure would tend to cause separation of the bond between the bars 12 and rib sections 2".

From the foregoing, it will now be appreciated that the present invention provides a split protector construction composed of identical parts Which are turned end for end and applied to a length of drill string between the stop collars simply by the driving of a suitable number of bolts 10 into the recesses 12. When the bolts are tightened,-.the layers of rubber 6 and 17.1. between opposing flanges 6 and 7 are resilientlyedcfiormable so as to assist in locking the bolts 10- by resultant frictional engagement of the threads of stems 10" -in;.threaded openings 12. Y

However, inasmuch asthe bolt stems :10-'-loos, ely extend through flange openings 8 and =9, and;:additi on; lly since the fastener bars 12 are not fixedly connected to flanges 7, the respective protector sections aie relatively free for movement upon forceful engagementaof-seither section of the protector with the well wall as the .drill string rotates in thebore.

Such freedom of relativemovement, thong-h slight, serves to protect the components againsttdamaging forces which otherwise might tendto destroy them or the-metalto-rubber bond between the reinforcing inserts 4 ornthe bars 12 and the rib sections 2' and-:25".- gr

As previously mentioned, the protector is ':sueh.+that circulation of drilling fluids is not impaired"; andaddiftion, such drilling fluid is-effectively employed as'avlubricant to avoid excessive wear either 'of thead-rillrs'tringror the protectors-Accordingly,"as best -seenwin FlG. '2; the body 1 of the protector has an inside diameter'rgreater than the pipe string on which it is disposed to allow for the flow of drilling fluid therebetween. In. addition,--fiuid passages 1' are provided, extending longitudinallyeinthe inner periphery of the protector so as to conduct drilling fluid along the inner periphery of the protector even though at different times during rotation of the. drill string it may frictionally engage the protector body. at various angularly spaced locations.

It'will now be evident that the presentinvention pie; vides a split, non-rotating drill string protectonwhich' is simple in construction, being composed of'identicai halfsections, is simple to install, requiring merely the tighteri ing of a number of bolts, and is durable in use, being al ways lubricated and constructed to withstand heavy shock loads and vibration, as well as being safe in that it is not subject to loss of components within the well.

While specific structural deta ls have been shown and described, it should be understood that changes and a1- terations may be resorted to withoutdeparting from the spirit of the invention as defined in the appended claims.

We claim:

1. A tubular protector member capablev of'being applied about a portion'of a well drillingstrin g, the tubular member comprising arcuate section segments of elastomeric material, each segment including 'a pair of longitudinal connecting ribs of elastomeric material, each rib complementarily engaging a rib of an adjacent segmentof the tubular member, the segments having rigid inserts therein, wherein the improvement comprises:

(a) said inserts each including a pairof'longitudinal edge flanges, one of each pairextendin'g into one of each of said pairs of ribs, said ribs and' said flanges having spaced aligned lateral holes'ther'ethrough;""

(b) a bar embedded in the elastomeric material of "one of said ribs adjacent to one of eachof said-"pair's or edge flanges in eachof said segments, said bars having longitudinally spaced fastener means; and p (c) said fastener means being engaged by fasteners through said holes in one of said ribs and said flanges for securing saidflanges'together'in opposed 'relation to form said tubular member.

2. A tubular protector member as defined in claim 1 wherein a layer of elastomeric material in said ribs is interposed between said complementaryflanges of said-tubular member, whereby said elastomeric material is resiliently deformable when said fasteners are securedto's aid fastener means; l v

3. A tubular protector member as defined in claim 1 wherein said bar is bonded to said elastomeric material in said one of said ribs and is slidably contiguous withsaid one of each of said pairs of edge flanges;,is aid fas'tener means in said bar comprises threaded openingsland said References Cited UNITED STATES PATENTS Wright 287-5203 Hanes 3084 Clark 285-373 Decker 3084 Medearis 308-4 Williams 3084 11/1957 Swart 3084 4/ 1960 Le Bourg 3084 1/1962 Collett 3084 7/1965 Fairchild 3084 7/1965 Holombe 3084 1/ 1965 Hall 3084 FOREIGN PATENTS 1/ 1944 Germatny. 2/ 1961 Great Britain.

MARTIN P. SCHWADRON, Primary Examiner.

L. L. JOHNSON, Assistant Examiner. 

